AC generators for vehicles equipped with a pulley fastened on one axial end of a shaft and running torque is transmitted to the shaft from an internal-combustion engine through the pulley are well-known in general, for example.
Moreover, the pulley has an approximately cylindrical space that opens to the one end in the axial direction of the shaft (refer to drawings of Japanese Patent Application Laid-Open Publication No. 2006-046571), and a nut etc. used for fastening the shaft and the pulley are accommodated in the space (hereafter called the pulley space).
By the way, although the pulley space is covered by, for example, press-fitting a plate-like cap, a misaligning of the cap at the time of press-fitting is likely.
That is, there is a possibility that a press-fit-state of the cap may become unstable by an inclining or a misaligning of the cap in a depth direction (i.e., an axial direction of the shaft: hereafter called the axial direction) of the pulley space.
Therefore, manufacturing of the rotating electrical machine requires methods, equipment, etc. that can suppress the inclination and misalignment of the cap at the time of press-fitting the cap into the pulley.
In addition, Japanese Patent Application Laid-Open Publication No. 10-250712 discloses a technical idea that forms a female screw in an opening edge of a space, while a male screw is formed in a plug that blocks the opening of the space, and the plug is screwed lightly into the opening edge so that the plug is in a temporary fixed state.
According to the technical idea of '712, since the position, etc, of the plug are stabilized by screw-fastening with the application of the technical idea of '712, the inclination and misalignment of the cap can be suppressed on the opening edge of the pulley space of the rotating electrical machine and the cap.
However, since the steps of forming the screw in the opening edge of the pulley space and the cap, and the step of screw-fastening of the cap to the opening edge are required, the manufacturing steps become complicated.